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linux: Refactor ptrace usage.

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1) Add PtraceConnection which serves as the base class for specific
types of connections Crashpad uses to trace processes.
2) Add DirectPtraceConnection which is used when the handler process
has `ptrace` capabilities for the target process.
3) Move `ptrace` logic into Ptracer. This class isolates `ptrace` call
logic for use by various PtraceConnection implementations.

Bug: crashpad:30
Change-Id: I98083134a9f7d9f085e4cc816d2b85ffd6d73162
Reviewed-on: https://chromium-review.googlesource.com/671659
Commit-Queue: Joshua Peraza <jperaza@chromium.org>
Reviewed-by: Mark Mentovai <mark@chromium.org>
Reviewed-by: Leonard Mosescu <mosescu@chromium.org>
This commit is contained in:
Joshua Peraza 2017-09-22 09:14:52 -07:00
parent be7b8a509c
commit 59c5d848e5
26 changed files with 944 additions and 502 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
snapshot/linux/exception_snapshot_linux_test.cc
View File

@ -28,6 +28,7 @@
#include "snapshot/linux/process_reader.h"
#include "sys/syscall.h"
#include "test/errors.h"
#include "test/linux/fake_ptrace_connection.h"
#include "util/linux/address_types.h"
#include "util/misc/clock.h"
#include "util/misc/from_pointer_cast.h"
@ -96,8 +97,11 @@ void ExpectContext(const CPUContext& actual, const NativeCPUContext& expected) {
#endif
TEST(ExceptionSnapshotLinux, SelfBasic) {
FakePtraceConnection connection;
ASSERT_TRUE(connection.Initialize(getpid()));
ProcessReader process_reader;
ASSERT_TRUE(process_reader.Initialize(getpid()));
ASSERT_TRUE(process_reader.Initialize(&connection));
siginfo_t siginfo;
siginfo.si_signo = SIGSEGV;
@ -170,8 +174,11 @@ class RaiseTest {
private:
static void HandleRaisedSignal(int signo, siginfo_t* siginfo, void* context) {
FakePtraceConnection connection;
ASSERT_TRUE(connection.Initialize(getpid()));
ProcessReader process_reader;
ASSERT_TRUE(process_reader.Initialize(getpid()));
ASSERT_TRUE(process_reader.Initialize(&connection));
internal::ExceptionSnapshotLinux exception;
ASSERT_TRUE(exception.Initialize(&process_reader,
@ -230,8 +237,11 @@ class TimerTest {
private:
static void HandleTimer(int signo, siginfo_t* siginfo, void* context) {
FakePtraceConnection connection;
ASSERT_TRUE(connection.Initialize(getpid()));
ProcessReader process_reader;
ASSERT_TRUE(process_reader.Initialize(getpid()));
ASSERT_TRUE(process_reader.Initialize(&connection));
internal::ExceptionSnapshotLinux exception;
ASSERT_TRUE(exception.Initialize(&process_reader,

54
snapshot/linux/process_reader.cc
View File

@ -20,6 +20,7 @@
#include <stdio.h>
#include <string.h>
#include <sys/resource.h>
#include <unistd.h>
#include <algorithm>
@ -43,9 +44,7 @@ bool ShouldMergeStackMappings(const MemoryMap::Mapping& stack_mapping,
} // namespace
ProcessReader::Thread::Thread()
: thread_context(),
float_context(),
thread_specific_data_address(0),
: thread_info(),
stack_region_address(0),
stack_region_size(0),
tid(-1),
@ -54,19 +53,8 @@ ProcessReader::Thread::Thread()
ProcessReader::Thread::~Thread() {}
bool ProcessReader::Thread::InitializePtrace() {
ThreadInfo thread_info;
if (!thread_info.Initialize(tid)) {
return false;
}
thread_info.GetGeneralPurposeRegisters(&thread_context);
if (!thread_info.GetFloatingPointRegisters(&float_context)) {
return false;
}
if (!thread_info.GetThreadArea(&thread_specific_data_address)) {
bool ProcessReader::Thread::InitializePtrace(PtraceConnection* connection) {
if (!connection->GetThreadInfo(tid, &thread_info)) {
return false;
}
@ -101,11 +89,11 @@ bool ProcessReader::Thread::InitializePtrace() {
void ProcessReader::Thread::InitializeStack(ProcessReader* reader) {
LinuxVMAddress stack_pointer;
#if defined(ARCH_CPU_X86_FAMILY)
stack_pointer =
reader->Is64Bit() ? thread_context.t64.rsp : thread_context.t32.esp;
stack_pointer = reader->Is64Bit() ? thread_info.thread_context.t64.rsp
: thread_info.thread_context.t32.esp;
#elif defined(ARCH_CPU_ARM_FAMILY)
stack_pointer =
reader->Is64Bit() ? thread_context.t64.sp : thread_context.t32.sp;
stack_pointer = reader->Is64Bit() ? thread_info.thread_context.t64.sp
: thread_info.thread_context.t32.sp;
#else
#error Port.
#endif
@ -171,14 +159,16 @@ void ProcessReader::Thread::InitializeStack(ProcessReader* reader) {
// the stack region.
stack_region_size = stack_end - stack_region_address;
if (tid != reader->ProcessID() &&
thread_specific_data_address > stack_region_address &&
thread_specific_data_address < stack_end) {
stack_region_size = thread_specific_data_address - stack_region_address;
thread_info.thread_specific_data_address > stack_region_address &&
thread_info.thread_specific_data_address < stack_end) {
stack_region_size =
thread_info.thread_specific_data_address - stack_region_address;
}
}
ProcessReader::ProcessReader()
: process_info_(),
: connection_(),
process_info_(),
memory_map_(),
threads_(),
process_memory_(),
@ -188,12 +178,16 @@ ProcessReader::ProcessReader()
ProcessReader::~ProcessReader() {}
bool ProcessReader::Initialize(pid_t pid) {
bool ProcessReader::Initialize(PtraceConnection* connection) {
INITIALIZATION_STATE_SET_INITIALIZING(initialized_);
if (!process_info_.Initialize(pid)) {
DCHECK(connection);
connection_ = connection;
if (!process_info_.InitializeWithPtrace(connection_)) {
return false;
}
pid_t pid = connection->GetProcessID();
if (!memory_map_.Initialize(pid)) {
return false;
}
@ -203,9 +197,7 @@ bool ProcessReader::Initialize(pid_t pid) {
return false;
}
if (!process_info_.Is64Bit(&is_64_bit_)) {
return false;
}
is_64_bit_ = process_info_.Is64Bit();
INITIALIZATION_STATE_SET_VALID(initialized_);
return true;
@ -283,7 +275,7 @@ void ProcessReader::InitializeThreads() {
Thread main_thread;
main_thread.tid = pid;
if (main_thread.InitializePtrace()) {
if (main_thread.InitializePtrace(connection_)) {
main_thread.InitializeStack(this);
threads_.push_back(main_thread);
} else {
@ -311,7 +303,7 @@ void ProcessReader::InitializeThreads() {
Thread thread;
thread.tid = tid;
if (thread.InitializePtrace()) {
if (connection_->Attach(tid) && thread.InitializePtrace(connection_)) {
thread.InitializeStack(this);
threads_.push_back(thread);
}

14
snapshot/linux/process_reader.h
View File

@ -25,6 +25,7 @@
#include "util/linux/address_types.h"
#include "util/linux/memory_map.h"
#include "util/linux/process_memory.h"
#include "util/linux/ptrace_connection.h"
#include "util/linux/thread_info.h"
#include "util/posix/process_info.h"
#include "util/misc/initialization_state_dcheck.h"
@ -40,9 +41,7 @@ class ProcessReader {
Thread();
~Thread();
ThreadContext thread_context;
FloatContext float_context;
LinuxVMAddress thread_specific_data_address;
ThreadInfo thread_info;
LinuxVMAddress stack_region_address;
LinuxVMSize stack_region_size;
pid_t tid;
@ -53,7 +52,7 @@ class ProcessReader {
private:
friend class ProcessReader;
bool InitializePtrace();
bool InitializePtrace(PtraceConnection* connection);
void InitializeStack(ProcessReader* reader);
};
@ -63,11 +62,11 @@ class ProcessReader {
//! \brief Initializes this object.
//!
//! This method must be successfully called before calling any other method in
//! this class.
//! this class and may only be called once.
//!
//! \param[in] pid The process ID of the target process.
//! \param[in] connection A PtraceConnection to the target process.
//! \return `true` on success. `false` on failure with a message logged.
bool Initialize(pid_t pid);
bool Initialize(PtraceConnection* connection);
//! \brief Return `true` if the target task is a 64-bit process.
bool Is64Bit() const { return is_64_bit_; }
@ -111,6 +110,7 @@ class ProcessReader {
private:
void InitializeThreads();
PtraceConnection* connection_; // weak
ProcessInfo process_info_;
class MemoryMap memory_map_;
std::vector<Thread> threads_;

41
snapshot/linux/process_reader_test.cc
View File

@ -32,8 +32,10 @@
#include "build/build_config.h"
#include "gtest/gtest.h"
#include "test/errors.h"
#include "test/linux/fake_ptrace_connection.h"
#include "test/multiprocess.h"
#include "util/file/file_io.h"
#include "util/linux/direct_ptrace_connection.h"
#include "util/misc/from_pointer_cast.h"
#include "util/stdlib/pointer_container.h"
#include "util/synchronization/semaphore.h"
@ -69,13 +71,16 @@ LinuxVMAddress GetTLS() {
}
TEST(ProcessReader, SelfBasic) {
ProcessReader process_reader;
ASSERT_TRUE(process_reader.Initialize(getpid()));
FakePtraceConnection connection;
connection.Initialize(getpid());
#if !defined(ARCH_CPU_64_BITS)
EXPECT_FALSE(process_reader.Is64Bit());
#else
ProcessReader process_reader;
ASSERT_TRUE(process_reader.Initialize(&connection));
#if defined(ARCH_CPU_64_BITS)
EXPECT_TRUE(process_reader.Is64Bit());
#else
EXPECT_FALSE(process_reader.Is64Bit());
#endif
EXPECT_EQ(process_reader.ProcessID(), getpid());
@ -99,8 +104,11 @@ class BasicChildTest : public Multiprocess {
private:
void MultiprocessParent() override {
DirectPtraceConnection connection;
ASSERT_TRUE(connection.Initialize(ChildPID()));
ProcessReader process_reader;
ASSERT_TRUE(process_reader.Initialize(ChildPID()));
ASSERT_TRUE(process_reader.Initialize(&connection));
#if !defined(ARCH_CPU_64_BITS)
EXPECT_FALSE(process_reader.Is64Bit());
@ -255,18 +263,19 @@ void ExpectThreads(const ThreadMap& thread_map,
ASSERT_TRUE(memory_map.Initialize(pid));
for (const auto& thread : threads) {
SCOPED_TRACE(base::StringPrintf("Thread id %d, tls 0x%" PRIx64
", stack addr 0x%" PRIx64
", stack size 0x%" PRIx64,
SCOPED_TRACE(
base::StringPrintf("Thread id %d, tls 0x%" PRIx64
", stack addr 0x%" PRIx64 ", stack size 0x%" PRIx64,
thread.tid,
thread.thread_specific_data_address,
thread.thread_info.thread_specific_data_address,
thread.stack_region_address,
thread.stack_region_size));
const auto& iterator = thread_map.find(thread.tid);
ASSERT_NE(iterator, thread_map.end());
EXPECT_EQ(thread.thread_specific_data_address, iterator->second.tls);
EXPECT_EQ(thread.thread_info.thread_specific_data_address,
iterator->second.tls);
ASSERT_TRUE(memory_map.FindMapping(thread.stack_region_address));
EXPECT_LE(thread.stack_region_address, iterator->second.stack_address);
@ -305,8 +314,11 @@ class ChildThreadTest : public Multiprocess {
thread_map[tid] = expectation;
}
DirectPtraceConnection connection;
ASSERT_TRUE(connection.Initialize(ChildPID()));
ProcessReader process_reader;
ASSERT_TRUE(process_reader.Initialize(ChildPID()));
ASSERT_TRUE(process_reader.Initialize(&connection));
const std::vector<ProcessReader::Thread>& threads =
process_reader.Threads();
ExpectThreads(thread_map, threads, ChildPID());
@ -379,8 +391,11 @@ class ChildWithSplitStackTest : public Multiprocess {
CheckedReadFileExactly(ReadPipeHandle(), &stack_addr2, sizeof(stack_addr2));
CheckedReadFileExactly(ReadPipeHandle(), &stack_addr3, sizeof(stack_addr3));
DirectPtraceConnection connection;
ASSERT_TRUE(connection.Initialize(ChildPID()));
ProcessReader process_reader;
ASSERT_TRUE(process_reader.Initialize(ChildPID()));
ASSERT_TRUE(process_reader.Initialize(&connection));
const std::vector<ProcessReader::Thread>& threads =
process_reader.Threads();

7
snapshot/linux/system_snapshot_linux_test.cc
View File

@ -15,6 +15,7 @@
#include "snapshot/linux/system_snapshot_linux.h"
#include <sys/time.h>
#include <unistd.h>
#include <string>
@ -22,14 +23,18 @@
#include "gtest/gtest.h"
#include "snapshot/linux/process_reader.h"
#include "test/errors.h"
#include "test/linux/fake_ptrace_connection.h"
namespace crashpad {
namespace test {
namespace {
TEST(SystemSnapshotLinux, Basic) {
FakePtraceConnection connection;
ASSERT_TRUE(connection.Initialize(getpid()));
ProcessReader process_reader;
ASSERT_TRUE(process_reader.Initialize(getpid()));
ASSERT_TRUE(process_reader.Initialize(&connection));
timeval snapshot_time;
ASSERT_EQ(gettimeofday(&snapshot_time, nullptr), 0)

10
snapshot/linux/thread_snapshot_linux.cc
View File

@ -46,14 +46,14 @@ bool ThreadSnapshotLinux::Initialize(
if (process_reader->Is64Bit()) {
context_.architecture = kCPUArchitectureX86_64;
context_.x86_64 = &context_union_.x86_64;
InitializeCPUContextX86_64(thread.thread_context.t64,
thread.float_context.f64,
InitializeCPUContextX86_64(thread.thread_info.thread_context.t64,
thread.thread_info.float_context.f64,
context_.x86_64);
} else {
context_.architecture = kCPUArchitectureX86;
context_.x86 = &context_union_.x86;
InitializeCPUContextX86(thread.thread_context.t32,
thread.float_context.f32,
InitializeCPUContextX86(thread.thread_info.thread_context.t32,
thread.thread_info.float_context.f32,
context_.x86);
}
#else
@ -65,7 +65,7 @@ bool ThreadSnapshotLinux::Initialize(
thread.stack_region_size);
thread_specific_data_address_ =
thread.thread_specific_data_address;
thread.thread_info.thread_specific_data_address;
thread_id_ = thread.tid;

6
snapshot/mac/process_reader.cc
View File

@ -112,13 +112,11 @@ ProcessReader::~ProcessReader() {
bool ProcessReader::Initialize(task_t task) {
INITIALIZATION_STATE_SET_INITIALIZING(initialized_);
if (!process_info_.InitializeFromTask(task)) {
if (!process_info_.InitializeWithTask(task)) {
return false;
}
if (!process_info_.Is64Bit(&is_64_bit_)) {
return false;
}
is_64_bit_ = process_info_.Is64Bit();
task_memory_.reset(new TaskMemory(task));
task_ = task;

74
test/linux/fake_ptrace_connection.cc Normal file
View File

@ -0,0 +1,74 @@
// Copyright 2017 The Crashpad Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "test/linux/fake_ptrace_connection.h"
#include "build/build_config.h"
#include "gtest/gtest.h"
namespace crashpad {
namespace test {
FakePtraceConnection::FakePtraceConnection()
: PtraceConnection(),
attachments_(),
pid_(-1),
is_64_bit_(false),
initialized_() {}
FakePtraceConnection::~FakePtraceConnection() {}
bool FakePtraceConnection::Initialize(pid_t pid) {
INITIALIZATION_STATE_SET_INITIALIZING(initialized_);
if (!Attach(pid)) {
return false;
}
pid_ = pid;
#if defined(ARCH_CPU_64_BITS)
is_64_bit_ = true;
#else
is_64_bit_ = false;
#endif
INITIALIZATION_STATE_SET_VALID(initialized_);
return true;
}
pid_t FakePtraceConnection::GetProcessID() {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
return pid_;
}
bool FakePtraceConnection::Attach(pid_t tid) {
bool inserted = attachments_.insert(tid).second;
EXPECT_TRUE(inserted);
return inserted;
}
bool FakePtraceConnection::Is64Bit() {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
return is_64_bit_;
}
bool FakePtraceConnection::GetThreadInfo(pid_t tid, ThreadInfo* info) {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
bool attached = attachments_.find(tid) != attachments_.end();
EXPECT_TRUE(attached);
return attached;
}
} // namespace test
} // namespace crashpad

68
test/linux/fake_ptrace_connection.h Normal file
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@ -0,0 +1,68 @@
// Copyright 2017 The Crashpad Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef CRASHPAD_TEST_LINUX_FAKE_PTRACE_CONNECTION_H_
#define CRASHPAD_TEST_LINUX_FAKE_PTRACE_CONNECTION_H_
#include <sys/types.h>
#include <set>
#include "base/macros.h"
#include "util/linux/ptrace_connection.h"
#include "util/misc/initialization_state_dcheck.h"
namespace crashpad {
namespace test {
//! \brief Stands-in where real PtraceConnections aren't available.
//!
//! This class performs basic EXPECTs that it is used correctly, but does not
//! execute any real `ptrace` calls or attachments.
class FakePtraceConnection : public PtraceConnection {
public:
FakePtraceConnection();
~FakePtraceConnection();
//! \brief Initializes this connection for the process whose process ID is
//! \a pid.
//!
//! \param[in] pid The process ID of the process to connect to.
//! \return `true` on success. `false` on failure with a message logged.
bool Initialize(pid_t pid);
// PtraceConnection:
pid_t GetProcessID() override;
bool Attach(pid_t tid) override;
//! \brief Returns `true` if the current process is 64-bit.
bool Is64Bit() override;
//! \brief Does not modify \a info.
bool GetThreadInfo(pid_t tid, ThreadInfo* info) override;
private:
std::set<pid_t> attachments_;
pid_t pid_;
bool is_64_bit_;
InitializationStateDcheck initialized_;
DISALLOW_COPY_AND_ASSIGN(FakePtraceConnection);
};
} // namespace test
} // namespace crashpad
#endif // CRASHPAD_TEST_LINUX_FAKE_PTRACE_CONNECTION_H_

2
test/test.gyp
View File

@ -38,6 +38,8 @@
'gtest_death_check.h',
'hex_string.cc',
'hex_string.h',
'linux/fake_ptrace_connection.cc',
'linux/fake_ptrace_connection.h',
'mac/dyld.cc',
'mac/dyld.h',
'mac/mach_errors.cc',

66
util/linux/direct_ptrace_connection.cc Normal file
View File

@ -0,0 +1,66 @@
// Copyright 2017 The Crashpad Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "util/linux/direct_ptrace_connection.h"
#include <memory>
namespace crashpad {
DirectPtraceConnection::DirectPtraceConnection()
: PtraceConnection(),
attachments_(),
pid_(-1),
ptracer_(),
initialized_() {}
DirectPtraceConnection::~DirectPtraceConnection() {}
bool DirectPtraceConnection::Initialize(pid_t pid) {
INITIALIZATION_STATE_SET_INITIALIZING(initialized_);
if (!Attach(pid) || !ptracer_.Initialize(pid)) {
return false;
}
pid_ = pid;
INITIALIZATION_STATE_SET_VALID(initialized_);
return true;
}
pid_t DirectPtraceConnection::GetProcessID() {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
return pid_;
}
bool DirectPtraceConnection::Attach(pid_t tid) {
std::unique_ptr<ScopedPtraceAttach> attach(new ScopedPtraceAttach);
if (!attach->ResetAttach(tid)) {
return false;
}
attachments_.push_back(attach.release());
return true;
}
bool DirectPtraceConnection::Is64Bit() {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
return ptracer_.Is64Bit();
}
bool DirectPtraceConnection::GetThreadInfo(pid_t tid, ThreadInfo* info) {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
return ptracer_.GetThreadInfo(tid, info);
}
} // namespace crashpad

65
util/linux/direct_ptrace_connection.h Normal file
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@ -0,0 +1,65 @@
// Copyright 2017 The Crashpad Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef CRASHPAD_UTIL_LINUX_DIRECT_PTRACE_CONNECTION_H_
#define CRASHPAD_UTIL_LINUX_DIRECT_PTRACE_CONNECTION_H_
#include <sys/types.h>
#include "base/macros.h"
#include "util/linux/ptrace_connection.h"
#include "util/linux/ptracer.h"
#include "util/linux/scoped_ptrace_attach.h"
#include "util/misc/initialization_state_dcheck.h"
#include "util/stdlib/pointer_container.h"
namespace crashpad {
//! \brief Manages a direct `ptrace` connection to a process.
//!
//! This class is used when the current process has `ptrace` capabilities for
//! the target process.
class DirectPtraceConnection : public PtraceConnection {
public:
DirectPtraceConnection();
~DirectPtraceConnection();
//! \brief Initializes this connection for the process whose process ID is
//! \a pid.
//!
//! The main thread of the process is automatically attached by this call.
//!
//! \param[in] pid The process ID of the process to connect to.
//! \return `true` on success. `false` on failure with a message logged.
bool Initialize(pid_t pid);
// PtraceConnection:
pid_t GetProcessID() override;
bool Attach(pid_t tid) override;
bool Is64Bit() override;
bool GetThreadInfo(pid_t tid, ThreadInfo* info) override;
private:
PointerVector<ScopedPtraceAttach> attachments_;
pid_t pid_;
Ptracer ptracer_;
InitializationStateDcheck initialized_;
DISALLOW_COPY_AND_ASSIGN(DirectPtraceConnection);
};
} // namespace crashpad
#endif // CRASHPAD_UTIL_LINUX_DIRECT_PTRACE_CONNECTION_H_

52
util/linux/ptrace_connection.h Normal file
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@ -0,0 +1,52 @@
// Copyright 2017 The Crashpad Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef CRASHPAD_UTIL_LINUX_PTRACE_CONNECTION_H_
#define CRASHPAD_UTIL_LINUX_PTRACE_CONNECTION_H_
#include <sys/types.h>
#include "util/linux/thread_info.h"
namespace crashpad {
//! \brief Provides an interface for making `ptrace` requests against a process
//! and its threads.
class PtraceConnection {
public:
virtual ~PtraceConnection() {}
//! \brief Returns the process ID of the connected process.
virtual pid_t GetProcessID() = 0;
//! \brief Adds a new thread to this connection.
//!
//! \param[in] tid The thread ID of the thread to attach.
//! \return `true` on success. `false` on failure with a message logged.
virtual bool Attach(pid_t tid) = 0;
//! \brief Returns `true` if connected to a 64-bit process.
virtual bool Is64Bit() = 0;
//! \brief Retrieves a ThreadInfo for a target thread.
//!
//! \param[in] tid The thread ID of the target thread.
//! \param[out] info Information about the thread.
//! \return `true` on success. `false` on failure with a message logged.
virtual bool GetThreadInfo(pid_t tid, ThreadInfo* info) = 0;
};
} // namespace crashpad
#endif // CRASHPAD_UTIL_LINUX_PTRACE_CONNECTION_H_

347
util/linux/ptracer.cc Normal file
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@ -0,0 +1,347 @@
// Copyright 2017 The Crashpad Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "util/linux/ptracer.h"
#include <linux/elf.h>
#include <string.h>
#include <sys/ptrace.h>
#include <sys/uio.h>
#include "base/logging.h"
#include "util/misc/from_pointer_cast.h"
#if defined(ARCH_CPU_X86_FAMILY)
#include <asm/ldt.h>
#endif
namespace crashpad {
namespace {
#if defined(ARCH_CPU_X86_FAMILY)
template <typename Destination>
bool GetRegisterSet(pid_t tid, int set, Destination* dest) {
iovec iov;
iov.iov_base = dest;
iov.iov_len = sizeof(*dest);
if (ptrace(PTRACE_GETREGSET, tid, reinterpret_cast<void*>(set), &iov) != 0) {
PLOG(ERROR) << "ptrace";
return false;
}
if (iov.iov_len != sizeof(*dest)) {
LOG(ERROR) << "Unexpected registers size";
return false;
}
return true;
}
bool GetFloatingPointRegisters32(pid_t tid, FloatContext* context) {
return GetRegisterSet(tid, NT_PRXFPREG, &context->f32.fxsave);
}
bool GetFloatingPointRegisters64(pid_t tid, FloatContext* context) {
return GetRegisterSet(tid, NT_PRFPREG, &context->f64.fxsave);
}
bool GetThreadArea32(pid_t tid,
const ThreadContext& context,
LinuxVMAddress* address) {
size_t index = (context.t32.xgs & 0xffff) >> 3;
user_desc desc;
if (ptrace(
PTRACE_GET_THREAD_AREA, tid, reinterpret_cast<void*>(index), &desc) !=
0) {
PLOG(ERROR) << "ptrace";
return false;
}
*address = desc.base_addr;
return true;
}
bool GetThreadArea64(pid_t tid,
const ThreadContext& context,
LinuxVMAddress* address) {
*address = context.t64.fs_base;
return true;
}
#elif defined(ARCH_CPU_ARM_FAMILY)
#if defined(ARCH_CPU_ARMEL)
// PTRACE_GETREGSET, introduced in Linux 2.6.34 (2225a122ae26), requires kernel
// support enabled by HAVE_ARCH_TRACEHOOK. This has been set for x86 (including
// x86_64) since Linux 2.6.28 (99bbc4b1e677a), but for ARM only since
// Linux 3.5.0 (0693bf68148c4). Older Linux kernels support PTRACE_GETREGS,
// PTRACE_GETFPREGS, and PTRACE_GETVFPREGS instead, which don't allow checking
// the size of data copied.
//
// Fortunately, 64-bit ARM support only appeared in Linux 3.7.0, so if
// PTRACE_GETREGSET fails on ARM with EIO, indicating that the request is not
// supported, the kernel must be old enough that 64-bit ARM isn’t supported
// either.
//
// TODO(mark): Once helpers to interpret the kernel version are available, add
// a DCHECK to ensure that the kernel is older than 3.5.
bool GetGeneralPurposeRegistersLegacy(pid_t tid, ThreadContext* context) {
if (ptrace(PTRACE_GETREGS, tid, nullptr, &context->t32) != 0) {
PLOG(ERROR) << "ptrace";
return false;
}
return true;
}
bool GetFloatingPointRegistersLegacy(pid_t tid, FloatContext* context) {
if (ptrace(PTRACE_GETFPREGS, tid, nullptr, &context->f32.fpregs) != 0) {
PLOG(ERROR) << "ptrace";
return false;
}
context->f32.have_fpregs = true;
if (ptrace(PTRACE_GETVFPREGS, tid, nullptr, &context->f32.vfp) != 0) {
switch (errno) {
case EINVAL:
// These registers are optional on 32-bit ARM cpus
break;
default:
PLOG(ERROR) << "ptrace";
return false;
}
} else {
context->f32.have_vfp = true;
}
return true;
}
#endif // ARCH_CPU_ARMEL
// Normally, the Linux kernel will copy out register sets according to the size
// of the struct that contains them. Tracing a 32-bit ARM process running in
// compatibility mode on a 64-bit ARM cpu will only copy data for the number of
// registers times the size of the register, which won't include any possible
// trailing padding in the struct. These are the sizes of the register data, not
// including any possible padding.
constexpr size_t kArmVfpSize = 32 * 8 + 4;
// Target is 32-bit
bool GetFloatingPointRegisters32(pid_t tid, FloatContext* context) {
context->f32.have_fpregs = false;
context->f32.have_vfp = false;
iovec iov;
iov.iov_base = &context->f32.fpregs;
iov.iov_len = sizeof(context->f32.fpregs);
if (ptrace(
PTRACE_GETREGSET, tid, reinterpret_cast<void*>(NT_PRFPREG), &iov) !=
0) {
switch (errno) {
#if defined(ARCH_CPU_ARMEL)
case EIO:
return GetFloatingPointRegistersLegacy(tid, context);
#endif // ARCH_CPU_ARMEL
case EINVAL:
// A 32-bit process running on a 64-bit CPU doesn't have this register
// set. It should have a VFP register set instead.
break;
default:
PLOG(ERROR) << "ptrace";
return false;
}
} else {
if (iov.iov_len != sizeof(context->f32.fpregs)) {
LOG(ERROR) << "Unexpected registers size";
return false;
}
context->f32.have_fpregs = true;
}
iov.iov_base = &context->f32.vfp;
iov.iov_len = sizeof(context->f32.vfp);
if (ptrace(
PTRACE_GETREGSET, tid, reinterpret_cast<void*>(NT_ARM_VFP), &iov) !=
0) {
switch (errno) {
case EINVAL:
// VFP may not be present on 32-bit ARM cpus.
break;
default:
PLOG(ERROR) << "ptrace";
return false;
}
} else {
if (iov.iov_len != kArmVfpSize && iov.iov_len != sizeof(context->f32.vfp)) {
LOG(ERROR) << "Unexpected registers size";
return false;
}
context->f32.have_vfp = true;
}
if (!(context->f32.have_fpregs || context->f32.have_vfp)) {
LOG(ERROR) << "Unable to collect registers";
return false;
}
return true;
}
bool GetFloatingPointRegisters64(pid_t tid, FloatContext* context) {
iovec iov;
iov.iov_base = context;
iov.iov_len = sizeof(*context);
if (ptrace(
PTRACE_GETREGSET, tid, reinterpret_cast<void*>(NT_PRFPREG), &iov) !=
0) {
PLOG(ERROR) << "ptrace";
return false;
}
if (iov.iov_len != sizeof(context->f64)) {
LOG(ERROR) << "Unexpected registers size";
return false;
}
return true;
}
bool GetThreadArea32(pid_t tid,
const ThreadContext& context,
LinuxVMAddress* address) {
#if defined(ARCH_CPU_ARMEL)
void* result;
if (ptrace(PTRACE_GET_THREAD_AREA, tid, nullptr, &result) != 0) {
PLOG(ERROR) << "ptrace";
return false;
}
*address = FromPointerCast<LinuxVMAddress>(result);
return true;
#else
// TODO(jperaza): it doesn't look like there is a way for a 64-bit ARM process
// to get the thread area for a 32-bit ARM process with ptrace.
LOG(WARNING) << "64-bit ARM cannot trace TLS area for a 32-bit process";
return false;
#endif // ARCH_CPU_ARMEL
}
bool GetThreadArea64(pid_t tid,
const ThreadContext& context,
LinuxVMAddress* address) {
iovec iov;
iov.iov_base = address;
iov.iov_len = sizeof(*address);
if (ptrace(
PTRACE_GETREGSET, tid, reinterpret_cast<void*>(NT_ARM_TLS), &iov) !=
0) {
PLOG(ERROR) << "ptrace";
return false;
}
if (iov.iov_len != 8) {
LOG(ERROR) << "address size mismatch";
return false;
}
return true;
}
#else
#error Port.
#endif // ARCH_CPU_X86_FAMILY
size_t GetGeneralPurposeRegistersAndLength(pid_t tid, ThreadContext* context) {
iovec iov;
iov.iov_base = context;
iov.iov_len = sizeof(*context);
if (ptrace(
PTRACE_GETREGSET, tid, reinterpret_cast<void*>(NT_PRSTATUS), &iov) !=
0) {
switch (errno) {
#if defined(ARCH_CPU_ARMEL)
case EIO:
if (GetGeneralPurposeRegistersLegacy(tid, context)) {
return sizeof(context->t32);
}
#endif // ARCH_CPU_ARMEL
default:
PLOG(ERROR) << "ptrace";
return 0;
}
}
return iov.iov_len;
}
bool GetGeneralPurposeRegisters32(pid_t tid, ThreadContext* context) {
if (GetGeneralPurposeRegistersAndLength(tid, context) !=
sizeof(context->t32)) {
LOG(ERROR) << "Unexpected registers size";
return false;
}
return true;
}
bool GetGeneralPurposeRegisters64(pid_t tid, ThreadContext* context) {
if (GetGeneralPurposeRegistersAndLength(tid, context) !=
sizeof(context->t64)) {
LOG(ERROR) << "Unexpected registers size";
return false;
}
return true;
}
} // namespace
Ptracer::Ptracer() : is_64_bit_(false), initialized_() {}
Ptracer::Ptracer(bool is_64_bit) : is_64_bit_(is_64_bit) {
INITIALIZATION_STATE_SET_INITIALIZING(initialized_);
INITIALIZATION_STATE_SET_VALID(initialized_);
}
Ptracer::~Ptracer() {}
bool Ptracer::Initialize(pid_t pid) {
INITIALIZATION_STATE_SET_INITIALIZING(initialized_);
ThreadContext context;
size_t length = GetGeneralPurposeRegistersAndLength(pid, &context);
if (length == sizeof(context.t64)) {
is_64_bit_ = true;
} else if (length == sizeof(context.t32)) {
is_64_bit_ = false;
} else {
LOG(ERROR) << "Unexpected registers size";
return false;
}
INITIALIZATION_STATE_SET_VALID(initialized_);
return true;
}
bool Ptracer::Is64Bit() {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
return is_64_bit_;
}
bool Ptracer::GetThreadInfo(pid_t tid, ThreadInfo* info) {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
if (is_64_bit_) {
return GetGeneralPurposeRegisters64(tid, &info->thread_context) &&
GetFloatingPointRegisters64(tid, &info->float_context) &&
GetThreadArea64(
tid, info->thread_context, &info->thread_specific_data_address);
}
return GetGeneralPurposeRegisters32(tid, &info->thread_context) &&
GetFloatingPointRegisters32(tid, &info->float_context) &&
GetThreadArea32(
tid, info->thread_context, &info->thread_specific_data_address);
}
} // namespace crashpad

78
util/linux/ptracer.h Normal file
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@ -0,0 +1,78 @@
// Copyright 2017 The Crashpad Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef CRASHPAD_UTIL_LINUX_PTRACER_H_
#define CRASHPAD_UTIL_LINUX_PTRACER_H_
#include <sys/types.h>
#include "base/macros.h"
#include "util/linux/address_types.h"
#include "util/linux/thread_info.h"
#include "util/misc/initialization_state_dcheck.h"
namespace crashpad {
//! \brief Provides an architecturally agnostic interface for collecting
//! information with `ptrace`.
//!
//! A ptracer is configured for a particular bitness. It is an error to make any
//! calls via this object against a thread whose bitness does not match the
//! bitness this object was initialized with.
class Ptracer {
public:
//! \brief Constructs this object with a pre-determined bitness.
//!
//! \param[in] is_64_bit `true` if this object is to be configured for 64-bit.
explicit Ptracer(bool is_64_bit);
//! \brief Constructs this object without a pre-determined bitness.
//!
//! Initialize() must be successfully called before making any other calls on
//! this object.
Ptracer();
~Ptracer();
//! \brief Initializes this object to the bitness of the process whose process
//! ID is \a pid.
//!
//! \param[in] pid The process ID of the process to initialize with.
//! \return `true` on success. `false` on failure with a message logged.
bool Initialize(pid_t pid);
//! \brief Return `true` if this object is configured for 64-bit.
bool Is64Bit();
//! \brief Uses `ptrace` to collect information about the thread with thread
//! ID \a tid.
//!
//! The target thread should be attached before calling this method.
//! \see ScopedPtraceAttach
//!
//! \param[in] tid The thread ID of the thread to collect information for.
//! \param[out] info A ThreadInfo for the thread.
//! \return `true` on success. `false` on failure with a message logged.
bool GetThreadInfo(pid_t tid, ThreadInfo* info);
private:
bool is_64_bit_;
InitializationStateDcheck initialized_;
DISALLOW_COPY_AND_ASSIGN(Ptracer);
};
} // namespace crashpad
#endif // CRASHPAD_UTIL_LINUX_PTRACER_H_

28
util/linux/thread_info_test.cc → util/linux/ptracer_test.cc
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@ -12,12 +12,13 @@
// See the License for the specific language governing permissions and
// limitations under the License.
#include "util/linux/thread_info.h"
#include "util/linux/ptracer.h"
#include "build/build_config.h"
#include "gtest/gtest.h"
#include "test/multiprocess.h"
#include "util/file/file_io.h"
#include "util/linux/scoped_ptrace_attach.h"
#include "util/misc/from_pointer_cast.h"
namespace crashpad {
@ -35,30 +36,27 @@ class SameBitnessTest : public Multiprocess {
CheckedReadFileExactly(
ReadPipeHandle(), &expected_tls, sizeof(expected_tls));
ThreadInfo thread_info;
ASSERT_TRUE(thread_info.Initialize(ChildPID()));
#if defined(ARCH_CPU_64_BITS)
constexpr bool am_64_bit = true;
#else
constexpr bool am_64_bit = false;
#endif // ARCH_CPU_64_BITS
EXPECT_EQ(thread_info.Is64Bit(), am_64_bit);
ScopedPtraceAttach attach;
ASSERT_TRUE(attach.ResetAttach(ChildPID()));
ThreadContext thread_context;
thread_info.GetGeneralPurposeRegisters(&thread_context);
Ptracer ptracer(am_64_bit);
EXPECT_EQ(ptracer.Is64Bit(), am_64_bit);
ThreadInfo thread_info;
ASSERT_TRUE(ptracer.GetThreadInfo(ChildPID(), &thread_info));
#if defined(ARCH_CPU_X86_64)
EXPECT_EQ(thread_context.t64.fs_base, expected_tls);
EXPECT_EQ(thread_info.thread_context.t64.fs_base, expected_tls);
#endif // ARCH_CPU_X86_64
FloatContext float_context;
EXPECT_TRUE(thread_info.GetFloatingPointRegisters(&float_context));
LinuxVMAddress tls_address;
ASSERT_TRUE(thread_info.GetThreadArea(&tls_address));
EXPECT_EQ(tls_address, expected_tls);
EXPECT_EQ(thread_info.thread_specific_data_address, expected_tls);
}
void MultiprocessChild() override {
@ -88,7 +86,7 @@ class SameBitnessTest : public Multiprocess {
DISALLOW_COPY_AND_ASSIGN(SameBitnessTest);
};
TEST(ThreadInfo, SameBitness) {
TEST(Ptracer, SameBitness) {
SameBitnessTest test;
test.Run();
}

301
util/linux/thread_info.cc
View File

@ -14,188 +14,10 @@
#include "util/linux/thread_info.h"
#include <linux/elf.h>
#include <string.h>
#include <sys/ptrace.h>
#include <sys/uio.h>
#include "base/logging.h"
#include "util/misc/from_pointer_cast.h"
#if defined(ARCH_CPU_X86_FAMILY)
#include <asm/ldt.h>
#endif
namespace crashpad {
namespace {
#if defined(ARCH_CPU_X86_FAMILY)
template <typename Destination>
bool GetRegisterSet(pid_t tid, int set, Destination* dest) {
iovec iov;
iov.iov_base = dest;
iov.iov_len = sizeof(*dest);
if (ptrace(PTRACE_GETREGSET, tid, reinterpret_cast<void*>(set), &iov) != 0) {
PLOG(ERROR) << "ptrace";
return false;
}
if (iov.iov_len != sizeof(*dest)) {
LOG(ERROR) << "Unexpected registers size";
return false;
}
return true;
}
bool GetFloatingPointRegisters32(pid_t tid, FloatContext* context) {
return GetRegisterSet(tid, NT_PRXFPREG, &context->f32.fxsave);
}
bool GetFloatingPointRegisters64(pid_t tid, FloatContext* context) {
return GetRegisterSet(tid, NT_PRFPREG, &context->f64.fxsave);
}
#elif defined(ARCH_CPU_ARM_FAMILY)
#if defined(ARCH_CPU_ARMEL)
// PTRACE_GETREGSET, introduced in Linux 2.6.34 (2225a122ae26), requires kernel
// support enabled by HAVE_ARCH_TRACEHOOK. This has been set for x86 (including
// x86_64) since Linux 2.6.28 (99bbc4b1e677a), but for ARM only since
// Linux 3.5.0 (0693bf68148c4). Older Linux kernels support PTRACE_GETREGS,
// PTRACE_GETFPREGS, and PTRACE_GETVFPREGS instead, which don't allow checking
// the size of data copied.
//
// Fortunately, 64-bit ARM support only appeared in Linux 3.7.0, so if
// PTRACE_GETREGSET fails on ARM with EIO, indicating that the request is not
// supported, the kernel must be old enough that 64-bit ARM isn’t supported
// either.
//
// TODO(mark): Once helpers to interpret the kernel version are available, add
// a DCHECK to ensure that the kernel is older than 3.5.
bool GetGeneralPurposeRegistersLegacy(pid_t tid, ThreadContext* context) {
if (ptrace(PTRACE_GETREGS, tid, nullptr, &context->t32) != 0) {
PLOG(ERROR) << "ptrace";
return false;
}
return true;
}
bool GetFloatingPointRegistersLegacy(pid_t tid, FloatContext* context) {
if (ptrace(PTRACE_GETFPREGS, tid, nullptr, &context->f32.fpregs) != 0) {
PLOG(ERROR) << "ptrace";
return false;
}
context->f32.have_fpregs = true;
if (ptrace(PTRACE_GETVFPREGS, tid, nullptr, &context->f32.vfp) != 0) {
switch (errno) {
case EINVAL:
// These registers are optional on 32-bit ARM cpus
break;
default:
PLOG(ERROR) << "ptrace";
return false;
}
} else {
context->f32.have_vfp = true;
}
return true;
}
#endif // ARCH_CPU_ARMEL
// Normally, the Linux kernel will copy out register sets according to the size
// of the struct that contains them. Tracing a 32-bit ARM process running in
// compatibility mode on a 64-bit ARM cpu will only copy data for the number of
// registers times the size of the register, which won't include any possible
// trailing padding in the struct. These are the sizes of the register data, not
// including any possible padding.
constexpr size_t kArmVfpSize = 32 * 8 + 4;
// Target is 32-bit
bool GetFloatingPointRegisters32(pid_t tid, FloatContext* context) {
context->f32.have_fpregs = false;
context->f32.have_vfp = false;
iovec iov;
iov.iov_base = &context->f32.fpregs;
iov.iov_len = sizeof(context->f32.fpregs);
if (ptrace(
PTRACE_GETREGSET, tid, reinterpret_cast<void*>(NT_PRFPREG), &iov) !=
0) {
switch (errno) {
#if defined(ARCH_CPU_ARMEL)
case EIO:
return GetFloatingPointRegistersLegacy(tid, context);
#endif // ARCH_CPU_ARMEL
case EINVAL:
// A 32-bit process running on a 64-bit CPU doesn't have this register
// set. It should have a VFP register set instead.
break;
default:
PLOG(ERROR) << "ptrace";
return false;
}
} else {
if (iov.iov_len != sizeof(context->f32.fpregs)) {
LOG(ERROR) << "Unexpected registers size";
return false;
}
context->f32.have_fpregs = true;
}
iov.iov_base = &context->f32.vfp;
iov.iov_len = sizeof(context->f32.vfp);
if (ptrace(
PTRACE_GETREGSET, tid, reinterpret_cast<void*>(NT_ARM_VFP), &iov) !=
0) {
switch (errno) {
case EINVAL:
// VFP may not be present on 32-bit ARM cpus.
break;
default:
PLOG(ERROR) << "ptrace";
return false;
}
} else {
if (iov.iov_len != kArmVfpSize && iov.iov_len != sizeof(context->f32.vfp)) {
LOG(ERROR) << "Unexpected registers size";
return false;
}
context->f32.have_vfp = true;
}
if (!(context->f32.have_fpregs || context->f32.have_vfp)) {
LOG(ERROR) << "Unable to collect registers";
return false;
}
return true;
}
// Target is 64-bit
bool GetFloatingPointRegisters64(pid_t tid, FloatContext* context) {
iovec iov;
iov.iov_base = context;
iov.iov_len = sizeof(*context);
if (ptrace(
PTRACE_GETREGSET, tid, reinterpret_cast<void*>(NT_PRFPREG), &iov) !=
0) {
PLOG(ERROR) << "ptrace";
return false;
}
if (iov.iov_len != sizeof(context->f64)) {
LOG(ERROR) << "Unexpected registers size";
return false;
}
return true;
}
#else
#error Port.
#endif // ARCH_CPU_X86_FAMILY
} // namespace
ThreadContext::ThreadContext() {
memset(this, 0, sizeof(*this));
}
@ -209,129 +31,8 @@ FloatContext::FloatContext() {
FloatContext::~FloatContext() {}
ThreadInfo::ThreadInfo()
: context_(), attachment_(), tid_(-1), initialized_(), is_64_bit_(false) {}
: thread_context(), float_context(), thread_specific_data_address(0) {}
ThreadInfo::~ThreadInfo() {}
bool ThreadInfo::Initialize(pid_t tid) {
INITIALIZATION_STATE_SET_INITIALIZING(initialized_);
if (!attachment_.ResetAttach(tid)) {
return false;
}
tid_ = tid;
size_t length = GetGeneralPurposeRegistersAndLength(&context_);
if (length == sizeof(context_.t64)) {
is_64_bit_ = true;
} else if (length == sizeof(context_.t32)) {
is_64_bit_ = false;
} else {
LOG(ERROR) << "Unexpected registers size";
return false;
}
INITIALIZATION_STATE_SET_VALID(initialized_);
return true;
}
bool ThreadInfo::Is64Bit() {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
return is_64_bit_;
}
void ThreadInfo::GetGeneralPurposeRegisters(ThreadContext* context) {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
*context = context_;
}
size_t ThreadInfo::GetGeneralPurposeRegistersAndLength(ThreadContext* context) {
iovec iov;
iov.iov_base = context;
iov.iov_len = sizeof(*context);
if (ptrace(
PTRACE_GETREGSET, tid_, reinterpret_cast<void*>(NT_PRSTATUS), &iov) !=
0) {
switch (errno) {
#if defined(ARCH_CPU_ARMEL)
case EIO:
if (GetGeneralPurposeRegistersLegacy(tid_, context)) {
return sizeof(context->t32);
}
#endif // ARCH_CPU_ARMEL
default:
PLOG(ERROR) << "ptrace";
return 0;
}
}
return iov.iov_len;
}
bool ThreadInfo::GetFloatingPointRegisters(FloatContext* context) {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
return is_64_bit_ ? GetFloatingPointRegisters64(tid_, context)
: GetFloatingPointRegisters32(tid_, context);
}
bool ThreadInfo::GetThreadArea(LinuxVMAddress* address) {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
#if defined(ARCH_CPU_X86_FAMILY)
if (is_64_bit_) {
*address = context_.t64.fs_base;
return true;
}
size_t index = (context_.t32.xgs & 0xffff) >> 3;
user_desc desc;
if (ptrace(PTRACE_GET_THREAD_AREA,
tid_,
reinterpret_cast<void*>(index),
&desc) != 0) {
PLOG(ERROR) << "ptrace";
return false;
}
*address = desc.base_addr;
return true;
#elif defined(ARCH_CPU_ARM_FAMILY)
if (is_64_bit_) {
iovec iov;
iov.iov_base = address;
iov.iov_len = sizeof(*address);
if (ptrace(PTRACE_GETREGSET,
tid_,
reinterpret_cast<void*>(NT_ARM_TLS),
&iov) != 0) {
PLOG(ERROR) << "ptrace";
return false;
}
if (iov.iov_len != 8) {
LOG(ERROR) << "address size mismatch";
return false;
}
return true;
}
#if defined(ARCH_CPU_ARMEL)
void* result;
if (ptrace(PTRACE_GET_THREAD_AREA, tid_, nullptr, &result) != 0) {
PLOG(ERROR) << "ptrace";
return false;
}
*address = FromPointerCast<LinuxVMAddress>(result);
return true;
#else
// TODO(jperaza): it doesn't look like there is a way for a 64-bit ARM process
// to get the thread area for a 32-bit ARM process with ptrace.
LOG(WARNING) << "64-bit ARM cannot trace TLS area for a 32-bit process";
return false;
#endif // ARCH_CPU_ARMEL
#else
#error Port.
#endif // ARCH_CPU_X86_FAMILY
}
} // namespace crashpad

62
util/linux/thread_info.h
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@ -16,15 +16,12 @@
#define CRASHPAD_UTIL_LINUX_THREAD_INFO_H_
#include <stdint.h>
#include <sys/types.h>
#include <sys/user.h>
#include <type_traits>
#include "build/build_config.h"
#include "util/linux/address_types.h"
#include "util/linux/scoped_ptrace_attach.h"
#include "util/misc/initialization_state_dcheck.h"
#include "util/numeric/int128.h"
#if defined(OS_ANDROID)
@ -245,62 +242,19 @@ union FloatContext {
static_assert(std::is_standard_layout<FloatContext>::value,
"Not standard layout");
class ThreadInfo {
public:
//! \brief A collection of `ptrace`-able information about a thread.
struct ThreadInfo {
ThreadInfo();
~ThreadInfo();
//! \brief Initializes this object with information about the thread whose ID
//! is \a tid.
//!
//! This method must be called successfully prior to calling any other method
//! in this class. This method may only be called once.
//!
//! It is unspecified whether the information that an object of this class
//! returns is loaded at the time Initialize() is called or subsequently, and
//! whether this information is cached in the object or not.
//!
//! \param[in] tid The thread ID to obtain information for.
//!
//! \return `true` on success, `false` on failure with a message logged.
bool Initialize(pid_t tid);
//! \brief The general purpose registers for the thread.
ThreadContext thread_context;
//! \brief Determines the target thread’s bitness.
//!
//! \return `true` if the target is 64-bit.
bool Is64Bit();
//! \brief The floating point registers for the thread.
FloatContext float_context;
//! \brief Uses `ptrace` to collect general purpose registers from the target
//! thread and places the result in \a context.
//!
//! \param[out] context The registers read from the target thread.
void GetGeneralPurposeRegisters(ThreadContext* context);
//! \brief Uses `ptrace` to collect floating point registers from the target
//! thread and places the result in \a context.
//!
//! \param[out] context The registers read from the target thread.
//!
//! \return `true` on success, with \a context set. Otherwise, `false` with a
//! message logged.
bool GetFloatingPointRegisters(FloatContext* context);
//! \brief Uses `ptrace` to determine the thread-local storage address for the
//! target thread and places the result in \a address.
//!
//! \param[out] address The address of the TLS area.
//!
//! \return `true` on success. `false` on failure with a message logged.
bool GetThreadArea(LinuxVMAddress* address);
private:
size_t GetGeneralPurposeRegistersAndLength(ThreadContext* context);
ThreadContext context_;
ScopedPtraceAttach attachment_;
pid_t tid_;
InitializationStateDcheck initialized_;
bool is_64_bit_;
//! \brief The thread-local storage address for the thread.
LinuxVMAddress thread_specific_data_address;
};
} // namespace crashpad

5
util/mac/service_management_test.mm
View File

@ -38,7 +38,7 @@ namespace {
// requiring that its argv[argc - 1] compare equal to last_arg.
void ExpectProcessIsRunning(pid_t pid, std::string& last_arg) {
ProcessInfo process_info;
ASSERT_TRUE(process_info.Initialize(pid));
ASSERT_TRUE(process_info.InitializeWithPid(pid));
// The process may not have called exec yet, so loop with a small delay while
// looking for the cookie.
@ -85,7 +85,8 @@ void ExpectProcessIsNotRunning(pid_t pid, std::string& last_arg) {
std::vector<std::string> job_argv;
while (tries--) {
ProcessInfo process_info;
if (!process_info.Initialize(pid) || !process_info.Arguments(&job_argv)) {
if (!process_info.InitializeWithPid(pid) ||
!process_info.Arguments(&job_argv)) {
// The PID was not found.
return;
}

4
util/mach/task_for_pid.cc
View File

@ -38,7 +38,7 @@ bool TaskForPIDGroupCheck(const ProcessInfo& process_info) {
std::set<gid_t> groups = process_info.AllGroups();
ProcessInfo process_info_self;
if (!process_info_self.Initialize(getpid())) {
if (!process_info_self.InitializeWithPid(getpid())) {
return false;
}
@ -114,7 +114,7 @@ bool TaskForPIDCheck(task_t task) {
// interface.
ProcessInfo process_info;
if (!process_info.InitializeFromTask(task)) {
if (!process_info.InitializeWithTask(task)) {
return false;
}

41
util/posix/process_info.h
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@ -33,6 +33,10 @@
#include <sys/sysctl.h>
#endif
#if defined(OS_LINUX) || defined(OS_ANDROID)
#include "util/linux/ptrace_connection.h"
#endif
namespace crashpad {
class ProcessInfo {
@ -40,6 +44,24 @@ class ProcessInfo {
ProcessInfo();
~ProcessInfo();
#if defined(OS_LINUX) || defined(OS_ANDROID) || DOXYGEN
//! \brief Initializes this object with information about the process whose ID
//! is \a pid using a PtraceConnection \a connection.
//!
//! This method must be called successfully prior to calling any other method
//! in this class. This method may only be called once.
//!
//! It is unspecified whether the information that an object of this class
//! returns is loaded at the time Initialize() is called or subsequently, and
//! whether this information is cached in the object or not.
//!
//! \param[in] connection A connection to the remote process.
//!
//! \return `true` on success, `false` on failure with a message logged.
bool InitializeWithPtrace(PtraceConnection* connection);
#endif // OS_LINUX || OS_ANDROID || DOXYGEN
#if defined(OS_MACOSX) || DOXYGEN
//! \brief Initializes this object with information about the process whose ID
//! is \a pid.
//!
@ -53,19 +75,18 @@ class ProcessInfo {
//! \param[in] pid The process ID to obtain information for.
//!
//! \return `true` on success, `false` on failure with a message logged.
bool Initialize(pid_t pid);
bool InitializeWithPid(pid_t pid);
#if defined(OS_MACOSX) || DOXYGEN
//! \brief Initializes this object with information about a process based on
//! its Mach task.
//!
//! This method serves as a stand-in for Initialize() and may be called in its
//! place with the same restrictions and considerations.
//! This method serves as a stand-in for InitializeWithPid() and may be called
//! in its place with the same restrictions and considerations.
//!
//! \param[in] task The Mach task to obtain information for.
//!
//! \return `true` on success, `false` on failure with an message logged.
bool InitializeFromTask(task_t task);
bool InitializeWithTask(task_t task);
#endif
//! \return The target task’s process ID.
@ -116,11 +137,8 @@ class ProcessInfo {
//! \brief Determines the target process’ bitness.
//!
//! \param[out] is_64_bit `true` if the target task is a 64-bit process.
//!
//! \return `true` on success, with \a is_64_bit set. Otherwise, `false` with
//! a message logged.
bool Is64Bit(bool* is_64_bit) const;
//! \return `true` if the target task is a 64-bit process.
bool Is64Bit() const;
//! \brief Determines the target process’ start time.
//!
@ -166,9 +184,8 @@ class ProcessInfo {
gid_t gid_;
gid_t egid_;
gid_t sgid_;
bool is_64_bit_;
mutable InitializationState start_time_initialized_;
mutable InitializationState is_64_bit_initialized_;
mutable bool is_64_bit_;
#endif
InitializationStateDcheck initialized_;

41
util/posix/process_info_linux.cc
View File

@ -21,7 +21,6 @@
#include "util/file/delimited_file_reader.h"
#include "util/file/file_reader.h"
#include "util/linux/proc_stat_reader.h"
#include "util/linux/thread_info.h"
#include "util/misc/lexing.h"
namespace crashpad {
@ -38,16 +37,16 @@ ProcessInfo::ProcessInfo()
egid_(-1),
sgid_(-1),
start_time_initialized_(),
is_64_bit_initialized_(),
is_64_bit_(false),
initialized_() {}
ProcessInfo::~ProcessInfo() {}
bool ProcessInfo::Initialize(pid_t pid) {
bool ProcessInfo::InitializeWithPtrace(PtraceConnection* connection) {
INITIALIZATION_STATE_SET_INITIALIZING(initialized_);
DCHECK(connection);
pid_ = pid;
pid_ = connection->GetProcessID();
is_64_bit_ = connection->Is64Bit();
{
char path[32];
@ -220,37 +219,9 @@ bool ProcessInfo::DidChangePrivileges() const {
return false;
}
bool ProcessInfo::Is64Bit(bool* is_64_bit) const {
bool ProcessInfo::Is64Bit() const {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
if (is_64_bit_initialized_.is_uninitialized()) {
is_64_bit_initialized_.set_invalid();
#if defined(ARCH_CPU_64_BITS)
constexpr bool am_64_bit = true;
#else
constexpr bool am_64_bit = false;
#endif
if (pid_ == getpid()) {
is_64_bit_ = am_64_bit;
} else {
ThreadInfo thread_info;
if (!thread_info.Initialize(pid_)) {
return false;
}
is_64_bit_ = thread_info.Is64Bit();
}
is_64_bit_initialized_.set_valid();
}
if (!is_64_bit_initialized_.is_valid()) {
return false;
}
*is_64_bit = is_64_bit_;
return true;
return is_64_bit_;
}
bool ProcessInfo::StartTime(timeval* start_time) const {

11
util/posix/process_info_mac.cc
View File

@ -27,7 +27,7 @@ ProcessInfo::ProcessInfo() : kern_proc_info_(), initialized_() {
ProcessInfo::~ProcessInfo() {
}
bool ProcessInfo::Initialize(pid_t pid) {
bool ProcessInfo::InitializeWithPid(pid_t pid) {
INITIALIZATION_STATE_SET_INITIALIZING(initialized_);
int mib[] = {CTL_KERN, KERN_PROC, KERN_PROC_PID, pid};
@ -54,7 +54,7 @@ bool ProcessInfo::Initialize(pid_t pid) {
return true;
}
bool ProcessInfo::InitializeFromTask(task_t task) {
bool ProcessInfo::InitializeWithTask(task_t task) {
pid_t pid;
kern_return_t kr = pid_for_task(task, &pid);
if (kr != KERN_SUCCESS) {
@ -62,7 +62,7 @@ bool ProcessInfo::InitializeFromTask(task_t task) {
return false;
}
return Initialize(pid);
return InitializeWithPid(pid);
}
pid_t ProcessInfo::ProcessID() const {
@ -132,10 +132,9 @@ bool ProcessInfo::DidChangePrivileges() const {
return kern_proc_info_.kp_proc.p_flag & P_SUGID;
}
bool ProcessInfo::Is64Bit(bool* is_64_bit) const {
bool ProcessInfo::Is64Bit() const {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
*is_64_bit = kern_proc_info_.kp_proc.p_flag & P_LP64;
return true;
return kern_proc_info_.kp_proc.p_flag & P_LP64;
}
bool ProcessInfo::StartTime(timeval* start_time) const {

40
util/posix/process_info_test.cc
View File

@ -30,6 +30,11 @@
#include "util/file/file_io.h"
#include "util/misc/implicit_cast.h"
#if defined(OS_LINUX) || defined(OS_ANDROID)
#include "util/linux/direct_ptrace_connection.h"
#include "test/linux/fake_ptrace_connection.h"
#endif
namespace crashpad {
namespace test {
namespace {
@ -74,12 +79,10 @@ void TestProcessSelfOrClone(const ProcessInfo& process_info) {
// The test executable isn’t expected to change privileges.
EXPECT_FALSE(process_info.DidChangePrivileges());
bool is_64_bit;
ASSERT_TRUE(process_info.Is64Bit(&is_64_bit));
#if defined(ARCH_CPU_64_BITS)
EXPECT_TRUE(is_64_bit);
EXPECT_TRUE(process_info.Is64Bit());
#else
EXPECT_FALSE(is_64_bit);
EXPECT_FALSE(process_info.Is64Bit());
#endif
// Test StartTime(). This program must have started at some time in the past.
@ -127,14 +130,21 @@ void TestSelfProcess(const ProcessInfo& process_info) {
TEST(ProcessInfo, Self) {
ProcessInfo process_info;
ASSERT_TRUE(process_info.Initialize(getpid()));
#if defined(OS_LINUX) || defined(OS_ANDROID)
FakePtraceConnection connection;
ASSERT_TRUE(connection.Initialize(getpid()));
ASSERT_TRUE(process_info.InitializeWithPtrace(&connection));
#else
ASSERT_TRUE(process_info.InitializeWithPid(getpid()));
#endif // OS_LINUX || OS_ANDROID
TestSelfProcess(process_info);
}
#if defined(OS_MACOSX)
TEST(ProcessInfo, SelfTask) {
ProcessInfo process_info;
ASSERT_TRUE(process_info.InitializeFromTask(mach_task_self()));
ASSERT_TRUE(process_info.InitializeWithTask(mach_task_self()));
TestSelfProcess(process_info);
}
#endif
@ -143,7 +153,13 @@ TEST(ProcessInfo, Pid1) {
// PID 1 is expected to be init or the system’s equivalent. This tests reading
// information about another process.
ProcessInfo process_info;
ASSERT_TRUE(process_info.Initialize(1));
#if defined(OS_LINUX) || defined(OS_ANDROID)
FakePtraceConnection connection;
ASSERT_TRUE(connection.Initialize(1));
ASSERT_TRUE(process_info.InitializeWithPtrace(&connection));
#else
ASSERT_TRUE(process_info.InitializeWithPid(1));
#endif
EXPECT_EQ(process_info.ProcessID(), implicit_cast<pid_t>(1));
EXPECT_EQ(process_info.ParentProcessID(), implicit_cast<pid_t>(0));
@ -165,8 +181,16 @@ class ProcessInfoForkedTest : public Multiprocess {
void MultiprocessParent() override {
const pid_t pid = ChildPID();
#if defined(OS_LINUX) || defined(OS_ANDROID)
DirectPtraceConnection connection;
ASSERT_TRUE(connection.Initialize(pid));
ProcessInfo process_info;
ASSERT_TRUE(process_info.Initialize(pid));
ASSERT_TRUE(process_info.InitializeWithPtrace(&connection));
#else
ProcessInfo process_info;
ASSERT_TRUE(process_info.InitializeWithPid(pid));
#endif // OS_LINUX || OS_ANDROID
EXPECT_EQ(process_info.ProcessID(), pid);
EXPECT_EQ(process_info.ParentProcessID(), getpid());

5
util/util.gyp
View File

@ -48,6 +48,8 @@
'linux/auxiliary_vector.cc',
'linux/auxiliary_vector.h',
'linux/checked_address_range.h',
'linux/direct_ptrace_connection.cc',
'linux/direct_ptrace_connection.h',
'linux/memory_map.cc',
'linux/memory_map.h',
'linux/proc_stat_reader.cc',
@ -56,6 +58,9 @@
'linux/process_memory.h',
'linux/process_memory_range.cc',
'linux/process_memory_range.h',
'linux/ptrace_connection.h',
'linux/ptracer.cc',
'linux/ptracer.h',
'linux/scoped_ptrace_attach.cc',
'linux/scoped_ptrace_attach.h',
'linux/thread_info.cc',

2
util/util_test.gyp
View File

@ -44,8 +44,8 @@
'linux/proc_stat_reader_test.cc',
'linux/process_memory_range_test.cc',
'linux/process_memory_test.cc',
'linux/ptracer_test.cc',
'linux/scoped_ptrace_attach_test.cc',
'linux/thread_info_test.cc',
'mac/launchd_test.mm',
'mac/mac_util_test.mm',
'mac/service_management_test.mm',